etherpad.com
This is real-time text editing with 2 or more people. It has a chat box on the right so you can discuss what you're doing. It is absolutely superb and the timeline feature lets you play back the creation of the text as it happened. Of course it also stores all your versions.

The reason I'm raving is that I had to help my sister complete a job application while I was at the office. We dumped the job spec into a pad and started editing. In a few hours we achieved what I'm absolutely certain would have taken at least double that (extra time for viewing changes and approving them via email or wiki-style product).


thymer.com
I use various apps for work but this is the one that promises to spice up productivity. I love the way this is focused on tasks, getting them in quickly and allows you to type invocations that remind me of life on Videosift. Your tasks naturally fall into a timeline and you can filter and edit quickly. You can start timetracking on any item, discuss and group tasks into very easily accessed projects.

It has a colourful look and feels nimble and refreshing. I'm using a mixture of Basecamp and Highrise for my needs but Basecamp seems like overkill as it doesn't see much use. This would be worth the 4 euros a month but there is a free account. I'd love to see them extend the concept to includes notes and files but these things evolve over time.